PHP 4.2.0 Release Announcement

External variables

The biggest change in PHP 4.2.0 concerns variable handling. External
variables (from the environment, the HTTP request, cookies or the web server)
are no longer registered in the global scope by default. The preferred
method of accessing these external variables is by using the new Superglobal
arrays, introduced in PHP 4.1.0. More information about this change:

Compatibility

The Apache Software Foundation recently released their first
General Availability version of Apache 2. PHP 4.2.0 will have
EXPERIMENTAL support for this version. You can
build a DSO module for Apache 2 with --with-apxs2. We do
not recommend that you use this in a production
environment.

PHP 4.2.0 still lacks certain key features on Mac OS X and
Darwin, and isn't officially supported by the PHP Group on
these platforms. Specifically, building PHP as a dynamically
loaded Apache module isn't supported at this time. PHP 4.3.0,
due to be released in August, 2002, will be the first PHP
release to officially support Mac OS X. It, along with future
Mac OS X and Apache releases, will enable full feature parity
with other PHP platforms. Update:Instructions on
overcoming these limitations

Improvements

PHP 4.2.0 includes several improvements:

External variables (from the environment, the HTTP request, cookies or
the web server) are no longer registered as global variables

Overhaul of the sockets extension

Highly improved performance with file uploads

The satellite and mailparse extensions were moved to PECL and are no longer
bundled with the official PHP release

The posix extension has been cleaned up

iconv handling has been improved

Output buffering support, which was introduced in PHP 4.1.0 has
been stabilized